An intramedullary (IM) nail, also known as an IM rod or inter-locking nail, is a long rigid rod used to treat fractures of bones of the body. When bone fracture occurs, an IM nail may be inserted (in some occasions forced) into the medullary cavity of the fractured bone to fix and maintain relative positional stability of the fractured bone parts. IM nails are particularly useful in treating fractures of long bones of the body.
A long bone has two joint ends connected to the joints. In a typical simple bone fracture case where a long bone is fractured into two bone fragments, each bone fragment would have a fractured end corresponding to each other, and at least one of the bone fragment is deviated from its original position due to the fracture in most cases. Thus, an IM nail may be inserted into the medullary cavity of the fractured long bone to fix the two bone fragments. Specifically, to place the IM nail into the medullary cavity of the fractured bone, the IM nail is inserted to the medullary cavity of one bone fragment from the fractured end. Then, the bone fragment can be forced back to its original position corresponding to the other bone fragment, and the IM nail can be pushed toward the medullary cavity of the other bone fragment such that the IM nail is located to be disposed between the fractured ends of the two bone fragments. Thus, the bone fragments can be fixed to the IM nail by a plurality of locking members, such as screws or pins. In a typical comminuted bone fracture case where a long bone is fractured into many (generally three or more) bone fragments, the IM nail may be fixed to the two bone fragments at the end of the comminuted long bone, and then the other bone fragments between these two bone fragments at the end may be disposed and fixed on the IM nail.
Generally, the IM nail may have a plurality of locking holes, such as screw holes and pin holes, such that the locking member (for example, a screw or a pin) may be used to lock the bone fragment to the IM nail. Fixing of the bone fragment to the IM nail may be done by drilling a hole on the bone fragment corresponding to the position of one of the locking holes of the IM nail such that the locking member may be inserted to the locking hole through the hole on the bone fragment. However, the fixing is generally difficult because the locking holes of the IM nail are hidden in the medullary cavity of the bone fragment and are difficult to locate.
Further, the length of the IM nail must be longer than the length of the bone fragment such that there will be an exposed part of the IM nail for the doctor to hold and locate the position of the IM nail within the medullary cavity of the bone fragment. Thus, to enable the bone fragment to be forced back to its original position, the IM nail must be forced to pass through the joint end of the bone fragment such that, when the bone fragment to be forced back to its original position corresponding to the other bone fragment, the doctor may push the exposed IM nail part from the joint end toward the medullary cavity of the other bone fragment. In this way, the pass-through of the IM nail may be destructive to the joint.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.